Disk drive head suspensions having integrated lead or wireless flexures are known and disclosed, for example, in the Shum U.S. Pat. No. 7,023,667. Suspensions such as those shown in the Shum patent include a flexure mounted to a stainless steel (i.e., a spring metal) load beam. The load beam has a rigid or beam region extending from a spring region. The flexure has a mounting or base region that attaches to the beam region of the load beam and a gimbal extending from the base region. The gimbal includes pair of laterally-spaced spring arms connected by a cross member, and a tongue extending from the cross member into the area between the spring arms. A head slider having read/write heads is mounted to a slider mounting area on the tongue. Conductive electrical leads or traces on the flexure extend over the gimbal to the slider mounting region. Sections of the traces overlaying stainless steel portions of the flexure are separated from the stainless steel by a dielectric insulating layer. When the suspension is operated in a disk drive, the spring region of the load beam controls the height at which the head slider flies over the spinning disk. The gimbal allows the head slider to resiliently move in pitch and roll directions during the drive operation.
The load beam spring region is configured to provide precise mechanical properties such as spring rate. Similarly, the flexure gimbal is configured to provide precise mechanical properties such as pitch and roll stiffness. In order to minimize the effects of the traces on these properties, the traces are sometimes routed off the load beam spring region and off the flexure spring arms at locations were the traces traverse these portions of the load beam and flexure. The stainless steel layer is typically removed from the sections of the traces that are routed off of the load beam spring region and flexure gimbal (i.e., the unsupported trace sections) to further reduce the impact of these components on the mechanical properties of the load beam spring region and flexure gimbal. Unfortunately, these mechanical performance advantages are achieved at the expense of detrimental impacts on the electrical performance of the flexure. Removing the stainless steel layer adjacent to the traces creates impedance mismatches along the length of the traces, thereby limiting the overall impedance and bandwidth of the circuit.
There remains, therefore, a continuing need for improved disk drive head suspensions and flexures. In particular, there is a need for suspensions and flexures having high-performance mechanical properties along with relatively low impedance and high bandwidth electrical characteristics. The suspension and flexure should also be relatively efficient to manufacture.